Geography 2412 Lecture Notes

Energy (Chap 9)

We will examine energy sources and uses, globally and in the US. We will assess the advantages and disadvantages of the various energy sources. We’ll look at environmental impacts, like global warming (Chap. 10).

Renewable vs. Non-renewable (know Fig. 9.1)

Non-renewable, mostly fossil fuel, sources make up the vast bulk of energy used globally and in the USA, with oil providing the largest share (measured in energy units, with BTUs the most common measure: See: http://www.webopedia.com/TERM/B/Btu.html. : Short for British thermal unit, an British standard unit of energy. One Btu is equal to the amount of heat required to raise the temperature of one pound of liquid water by 1 degree Fahrenheit at its maximum density, which occurs at a temperature of 39.1 degrees Fahrenheit. One Btu is equal to approximately 251.9 calories or 1055 joules.)

USA sources and consumption by land use (know Fig. 9.3)

Sources: Crude oil dominates US sources (39%), and almost 2/3 of it (24.8 quadrillion BTUs) are imported. Natural gas and coal are about equal at 22-23% each, as are renewables (mostly hydropower) and nuclear, at about 6 and 8% respectively.

Consumption: A bit more than a third each in residential and commercial heating and lighting and other uses (e.g., powering electronics, which is increasing steeply) and Industrial uses of all sorts, from smelting iron to building cars. 27% is used in transportation, a large proportion compared to other developed countries, associated with the US’s large land area and long-distance transport and travel systems (mostly cars and trucks rather than rail). Mostly oil applied to transportation, so that’s where we need efficiencies to reduce demand and reliance on imports.

Fossil Fuels

Why so dominant? They are accessible, have good utility/applicability to energy needs (e.g., oil for transport), have high energy content per mass; and can be transported in bulk (though as we’ll see, natural gas offers some technical distribution problems.)

A great debate rages about how much fossil fuel is available, especially estimate reserves of oil. As we have talked about several times, the “economic reserve” is an estimate of that amount of fuel that can be recovered under current and near-term economics and technologies.

Sec. 9.3: The Fossil Fuels (get a sense from the maps where the main reserves of coal, oil and natural gas are located)

As we have seen, modern systems for utilizing natural resources are good at meeting production and consumption demands, though of course with more or less negative environmental effects and more or less sustainability. Critics of the sustainability of industrial systems especially worry about our use of fossil fuels, which are technically fixed or non-renewable (we may look harder and find more reserves, and we may learn to extract them more efficiently and completely, but logic dictates that there is a finite amount), and, of course they worry about the env consequences of fossil fuels.

We’ll pay attention to the characteristics that makes these energy sources more or less useful, that is, their advantages and disadvantages.

Coal:

Most abundant of the fuels, widely distributed geographically, but China, Russia (and former Soviet Union states), and the USA have most of the world’s supply. Used for centuries, but rapid growth with industrial revolution after 1800, and only recently supplanted by oil and natural gas. Most US coal now comes from the Western states (coal got its start in the east, the famous coal fields of the Appalachian mts), where is near the surface and strip-mined, and has less sulfur per mass.

Advantages: abundant, cheap, can be converted into gas and liquid fuels.

Disadvantages: dangerous to mine and large land/env impacts from mining; dirty burning per unit of energy compared to the other fossil fuels. Also, China’s large supplies and rapid economic development suggest that coal will be important contributor to atmospheric carbon dioxide in the future.

Other problem: China has significant coal reserves, wishes to use them, and because coal burns with more CO2, SOX and NOX per unit of energy released, and because China is such a large and rapidly growing economy, China could become the chief source of carbon dioxide in future.

Crude Oil/Petroleum

Replaced coal as FF of choice in US and global after about 1950.

Advantages: high energy content per mass; stores easily; burns cleaner than coal; versatile in uses, especially useful in transport sector; easy to transport.

Disadvantages: more pollution per unit of energy than natural gas; spills during transport are major global concern, especially for ocean and coastal ecosystems; not as abundant and being depleted---maybe 100 years left, and decline in total global production bound to begin much sooner, though that date is hotly debated. US production maxed out in 1970-80. We increasingly rely on imports. This raises geo-political problems: this politically and economically links USA to nations with which we have political differences and tensions---Russia is becoming a major exporter. (see map from New York Times---now on this web site)

Natural Gas:

Advantages: cleanest burning per unit of energy; good use in heating; possible greater use in transportation.

Disadvantages: expensive and requires elaborate infrastructure to transport; not readily transported over seas like oil (so difficult to transport that natural gas that tends to pop out of the ground along with oil is simply burned off at the well head); least abundant fossil fuel.

Geography 2412 Lecture Notes

Energy (sec. 9.4 and 9.5 and 9.6)

Non-fossil Fuel Energy Sources:

Nuclear:

Grew rapidly after 1970, but now stuck at about 20% of U.S. electricity (about 8% of total energy consumption).

• Advantages: low air pollution (if containment works); less env impact than, say, coal; nearly inexhaustible supply (with reprocessing, breeder reactors).
• Disadvantages: safety concerns and record; waste disposal; difficult de-commissioning/clean-up of plants; links to weapons-grade materials.

Waste disposal : A federal project to bury waste at Yucca MT, Nevada now years behind schedule, but may go on-line despite protests. Transportation issues will re-emerge as important public, perhaps also associated with terrorism fears.

Renewables:

Biomass: Wood and gas and liquid fuels from crops (corn).

Wood: important in LDCs. Probably over-harvested in many places.

Bio-mass Liquid and Gas Fuels:

Advantages: renewable; widely available; cleaner than fossil fuels

Disadvantages: low energy content; competes with food and wood products (fuel vs food) in growing world; negative effects on soils.

Hydroelectric:

(7 of US electricity, 3% of all US energy consumed)

Advantages: low air pollution; relatively low tech; renewable; meets peak demand.

Disadvantages: large env impacts of dams and reservoirs: habitat loss; wildlife impacts; downstream effects;

Wind Power:

Advantages: clean; perpetual; diurnal; inexpensive, low tech, portable;

Disadvantages: intermittent; wind farms are eyesores and dangerous to birds like raptors.

Solar Energy:

Passive and active heating (air and water) designs used in homes and buildings.

Solar electric: electricity from photovoltaic cells: getting better. Portable; becoming more efficient; but still high-tech, and still intermittent and seasonal.

Conservation/Efficiency Sec. 9.7

This is a very important part of energy mix; by some counts per capita energy consumption is falling!

It is also a growing theme in US energy mix since oil price hikes of the 1970s, but has lost some ground in last decade of economic growth, especially in transportation.

There are some bright spots: Good success in heating and lighting, which is over 1/3 of US consumption. Pays off! There has been a per capita decline in energy over last two decades.

Industrial (1/5 of energy use) : last two decades: there has been a decline in energy use even as production has increased, so this means also a decline per unit of production.

A less-bright spot: Transportation: uses half the world’s oil (US fleet of vehicles alone uses 14% of world oil). Efficiency is up in most types of vehicles around the world, but consumption is also up per capita as more and more people drive more and more vehicles more distance; and as the vehicle fleet, especially in the US, comes to include more small trucks and sport utility vehicles---so the avewrge fuele efificncy of the American fleet has declined over the last decade!.